Pure devotees, who take transcendental pleasure in hearing and chanting the glories of the Lord, do not care for any kind of liberation; even if they are offered the five liberations, they refuse to accept them

Unless one is a completely pure devotee, one cannot enjoy the transcendental bliss derived from chanting and dancing in the ecstasy of the sankirtana movement. Such ecstasy is not possible for an ordinary devotee.
Purport on Srimad Bhagavatam 8.3.20-21

A pure devotee is he who loves Krishna, without any material desire. Such pure devotees are very rare. Even if they have got some ulterior desire, that will be removed very soon, because they have taken to the pure process of Krishna Consciousness.